tides
n. countablen. the regular rise and fall of the ocean's water level during the day. This happens because of the way the moon and sun pull on the Earth.
n. the periodic rise and fall of the sea level under the gravitational influence of the moon and the sun. Often used metaphorically to describe shifting trends or patterns.
The tides change twice a day.
We checked the local schedule for the tides before walking along the beach to ensure we wouldn't get trapped by rising water.
The rhythmic movement of the tides has shaped coastal ecosystems for millennia, dictating the feeding patterns of birds and the reproductive cycles of various marine organisms.
Usually appears in the plural form when referring to the general phenomenon; the singular form refers to a specific instance of rising or falling water.